Low Threshold Monopolar Motor Mapping for Resection of Motor-eloquent Brain Lesions in Children and Adolescents

2014 ◽  
Vol 75 (S 02) ◽  
Author(s):  
P. Schucht ◽  
K. Seidel ◽  
M. Murek ◽  
L. Stieglitz ◽  
N. Urwyler ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
Brain Lesions ◽  
Motor Mapping ◽  
Low Threshold

Low-threshold monopolar motor mapping for resection of lesions in motor eloquent areas in children and adolescents

2014 ◽  
Vol 13 (5) ◽  
pp. 572-578 ◽  
Author(s):  
Philippe Schucht ◽  
Kathleen Seidel ◽  
Michael Murek ◽  
Lennart Henning Stieglitz ◽  
Natalie Urwyler ◽  
...  
Keyword(s):  
Children And Adolescents ◽  
High Frequency ◽  
Primary Motor Cortex ◽  
Pediatric Patients ◽  
Neurological Deficits ◽  
Precentral Gyrus ◽  
Safe Procedure ◽  
Motor Mapping ◽  
Low Threshold ◽  
Frequency Train

Object Resection of lesions close to the primary motor cortex (M1) and the corticospinal tract (CST) is generally regarded as high-risk surgery due to reported rates of postoperative severe deficits of up to 50%. The authors' objective was to determine the feasibility and safety of low-threshold motor mapping and its efficacy for increasing the extent of lesion resection in the proximity of M1 and the CST in children and adolescents. Methods The authors analyzed 8 consecutive pediatric patients in whom they performed 9 resections for lesions within or close (≤ 10 mm) to M1 and/or the CST. Monopolar high-frequency motor mapping with train-of-five stimuli (pulse duration 500 μsec, interstimulus interval 4.0 msec, frequency 250 Hz) was used. The motor threshold was defined as the minimal stimulation intensity that elicited motor evoked potentials (MEPs) from target muscles (amplitude > 30 μV). Resection was performed toward M1 and the CST at sites negative to 1- to 3-mA high-frequency train-of-five stimulation. Results The M1 was identified through high-frequency train-of-five via application of varying low intensities. The lowest motor thresholds after final resection ranged from 1 to 9 mA in 8 cases and up to 18 mA in 1 case, indicating proximity to motor neurons. Intraoperative electroencephalography documented an absence of seizures during all surgeries. Two transient neurological deficits were observed, but there were no permanent deficits. Postoperative imaging revealed complete resection in 8 patients and a very small remnant (< 0.175 cm3) in 1 patient. Conclusions High-frequency train-of-five with a minimal threshold of 1–3 mA is a feasible and safe procedure for resections in the proximity of the CST. Thus, low-threshold motor mapping might help to expand the area for safe resection in pediatric patients with lesions located within the precentral gyrus and close to the CST, and may be regarded as a functional navigational tool. The additional use of continuous MEP monitoring serves as a safety feedback for the functional integrity of the CST, especially because the true excitability threshold in children is unknown.

scholarly journals Intraoperative mapping of pre-central motor cortex and subcortex: a proposal for supplemental cortical and novel subcortical maps to Penfield’s motor homunculus

2021 ◽  
Author(s):  
Prajwal Ghimire ◽  
Jose Pedro Lavrador ◽  
Asfand Baig Mirza ◽  
Noemia Pereira ◽  
Hannah Keeble ◽  
...  
Keyword(s):  
Brain Mapping ◽  
Retrospective Cohort ◽  
Corticospinal Tract ◽  
Brain Lesions ◽  
Body Parts ◽  
Single Institution ◽  
Motor Representation ◽  
Motor Mapping ◽  
Subcortical Stimulation ◽  
Motor Maps

AbstractPenfield’s motor homunculus describes a caricaturised yet useful representation of the map of various body parts on the pre-central cortex. We propose a supplemental map of the clinically represented areas of human body in pre-central cortex and a novel subcortical corticospinal tract map. We believe this knowledge is essential for safe surgery in patients with eloquent brain lesions. A single-institution retrospective cohort study of patients who underwent craniotomy for motor eloquent lesions with intraoperative motor neuromonitoring (cortical and subcortical) between 2015 and 2020 was performed. All positive cortical and subcortical stimulation points were taken into account and cartographic maps were produced to demonstrate cortical and subcortical areas of motor representation and their configuration. A literature review in PubMed was performed. One hundred and eighty consecutive patients (58.4% male, 41.6% female) were included in the study with 81.6% asleep and 18.4% awake craniotomies for motor eloquent lesions (gliomas 80.7%, metastases 13.8%) with intraoperative cortical and subcortical motor mapping. Based on the data, we propose a supplemental clinical cortical and a novel subcortical motor map to the original Penfield’s motor homunculus, including demonstration of localisation of intercostal muscles both in the cortex and subcortex which has not been previously described. The supplementary clinical cortical and novel subcortical motor maps of the homunculus presented here have been derived from a large cohort of patients undergoing direct cortical and subcortical brain mapping. The information will have direct relevance for improving the safety and outcome of patients undergoing resection of motor eloquent brain lesions.

Low-Threshold Monopolar Motor Mapping for Resection of Primary Motor Cortex Tumors

2012 ◽  
Vol 71 (suppl_1) ◽  
pp. ons104-ons115 ◽  
Author(s):  
Kathleen Seidel ◽  
Jürgen Beck ◽  
Lennart Stieglitz ◽  
Philippe Schucht ◽  
Andreas Raabe
Keyword(s):  
Motor Neurons ◽  
Evoked Potential ◽  
Primary Motor Cortex ◽  
Motor Evoked Potential ◽  
National Institutes Of Health ◽  
Motor Deficit ◽  
Motor Threshold ◽  
Motor Mapping ◽  
Low Threshold ◽  
A Minor

Abstract BACKGROUND: Microsurgery within eloquent cortex is a controversial approach because of the high risk of permanent neurological deficit. Few data exist showing the relationship between the mapping stimulation intensity required for eliciting a muscle motor evoked potential and the distance to the motor neurons; furthermore, the motor threshold at which no deficit occurs remains to be defined. OBJECTIVE: To evaluate the safety of low threshold motor evoked potential mapping for tumor resection close to the primary motor cortex. METHODS: Fourteen patients undergoing tumor surgery were included. Motor threshold was defined as the stimulation intensity that elicited motor evoked potentials from target muscles (amplitude &gt; 30 μV). Monopolar high-frequency motor mapping with train-of-5 stimuli (HF-TOF; pulse duration = 500 microseconds; interstimulus interval = 4.0 milliseconds; frequency = 250 Hz) was used to determine motor response--negative sites where incision and dissection could be performed. At sites negative to 3-mA HF-TOF stimulation, the tumor was resected. RESULTS: HF-TOF mapping localized the motor neurons within the precentral gyrus by using variable, low-stimulation intensities. The lowest motor thresholds after final resection ranged from 3 to 6 mA, indicating close proximity of motor neurons. Postoperatively, 12 patients had no new motor deficit, 1 patient had a minor new temporary deficit (M4+, National Institutes of Health Stroke Scale 1), and another patient had a minor new permanent deficit (M4+, National Institutes of Health Stroke Scale 2). Thirteen patients had complete or gross total resection. CONCLUSION: These preliminary data demonstrate that a monopolar HF-TOF threshold &gt; 3 mA was not associated with a significant new motor deficit.

scholarly journals Short-Interval Intracortical Facilitation Improves Efficacy in nTMS Motor Mapping of Lower Extremity Muscle Representations in Patients with Supra-Tentorial Brain Tumors

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3233
Author(s):  
Haosu Zhang ◽  
Petro Julkunen ◽  
Axel Schröder ◽  
Anna Kelm ◽  
Sebastian Ille ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Corticospinal Tract ◽  
Short Interval ◽  
Single Pulse ◽  
Brain Lesions ◽  
Motor Mapping ◽  
Lower Extremity Muscle ◽  
Biphasic Pulse ◽  
Motor Maps ◽  
Using Data

Navigated transcranial magnetic stimulation (nTMS) is increasingly used for mapping of motor function prior to surgery in patients harboring motor-eloquent brain lesions. To date, single-pulse nTMS (sp-nTMS) has been predominantly used for this purpose, but novel paired-pulse nTMS (pp-nTMS) with biphasic pulse application has been made available recently. The purpose of this study was to systematically evaluate pp-nTMS with biphasic pulses in comparison to conventionally used sp-nTMS for preoperative motor mapping of lower extremity (lE) muscle representations. Thirty-nine patients (mean age: 56.3 ± 13.5 years, 69.2% males) harboring motor-eloquent brain lesions of different entity underwent motor mapping of lE muscle representations in lesion-affected hemispheres and nTMS-based tractography of the corticospinal tract (CST) using data from sp-nTMS and pp-nTMS with biphasic pulses, respectively. Compared to sp-nTMS, pp-nTMS enabled motor mapping with lower stimulation intensities (61.8 ± 13.8% versus 50.7 ± 11.6% of maximum stimulator output, p < 0.0001), and it provided reliable motor maps even in the most demanding cases where sp-nTMS failed (pp-nTMS was able to provide a motor map in five patients in whom sp-nTMS did not provide any motor-positive points, and pp-nTMS was the only modality to provide a motor map in one patient who also did not show motor-positive points during intraoperative stimulation). Fiber volumes of the tracked CST were slightly higher when motor maps of pp-nTMS were used, and CST tracking using pp-nTMS data was also possible in the five patients in whom sp-nTMS failed. In conclusion, application of pp-nTMS with biphasic pulses enables preoperative motor mapping of lE muscle representations even in the most challenging patients in whom the motor system is at high risk due to lesion location or resection.

scholarly journals Intraoperative mapping of pre-central motor cortex and subcortex: a proposal for supplemental cortical and novel subcortical maps to Penfield’s motor homunculus

2020 ◽  
Author(s):  
Prajwal Ghimire ◽  
Jose Lavrador ◽  
Asfand Mirza ◽  
Noemia Pereira ◽  
Hannah Keeble ◽  
...  
Keyword(s):  
Brain Mapping ◽  
Retrospective Cohort ◽  
Corticospinal Tract ◽  
Brain Lesions ◽  
Body Parts ◽  
Single Institution ◽  
Motor Representation ◽  
Motor Mapping ◽  
Subcortical Stimulation ◽  
Motor Maps

Abstract Introduction: Penfield’s motor homunculus describes a caricaturised yet useful representation of the map of various body parts on the pre-central cortex. We propose a supplemental map of the clinically represented areas of human body in pre-central cortex and a novel subcortical corticospinal tract map that are accurate and essential for safe surgery in patients with eloquent brain lesions. Materials and methods: A single-institution retrospective cohort study of patients who underwent craniotomy for motor eloquent lesions with intraoperative motor neuromonitoring (cortical and subcortical) between 2015 and 2020 was performed. All positive cortical and subcortical stimulation points were taken into account and cartographic maps were produced to demonstrate cortical and subcortical areas of motor representation and their configuration. A literature review in PubMed was performed. Results: 180 patients (58.4% male, 41.6% female) were included in the study with 81.6% asleep and 18.4% awake craniotomies for motor eloquent lesions (gliomas 80.7%, metastases 13.8%) with intraoperative cortical and subcortical motor mapping. Based on the data, we propose a supplemental clinical cortical and a novel subcortical motor map to the original Penfield’s motor homunculus, including demonstration of localisation of intercostal muscles both in the cortex and subcortex which has not been previously described. Conclusion: The supplementary clinical cortical and novel subcortical motor maps of the homunculus presented here have been derived from a large cohort of patients undergoing direct cortical and subcortical brain mapping. The information will have direct relevance for improving the safety and outcome of patients undergoing resection of motor eloquent brain lesions.

scholarly journals “The Buoy”: Utilization of a low-threshold ambulatory setting for traumatized children and adolescents in Austria

2016 ◽  
Vol 30 (1) ◽  
pp. 27-32 ◽  
Author(s):  
J. Huemer ◽  
S. Völkl-Kernstock ◽  
A. Yee ◽  
T. Bruckner ◽  
Katrin Skala
Keyword(s):  
Children And Adolescents ◽  
Ambulatory Setting ◽  
Traumatized Children ◽  
Low Threshold

Analyzing the Potential Benefit of Microcomputer Use for Teaching Figurative Language

1992 ◽  
Vol 1 (2) ◽  
pp. 36-43 ◽  
Author(s):  
Marilyn A. Nippold ◽  
Ilsa E. Schwarz ◽  
Molly Lewis
Keyword(s):  
Language Learning ◽  
Children And Adolescents ◽  
Standardized Tests ◽  
Figurative Language ◽  
Language Intervention ◽  
School Age Children ◽  
Educational Materials ◽  
Language Learning Disabilities ◽  
Promising Application ◽  
Experience Difficulty

Microcomputers offer the potential for increasing the effectiveness of language intervention for school-age children and adolescents who have language-learning disabilities. One promising application is in the treatment of students who experience difficulty comprehending figurative expressions, an aspect of language that occurs frequently in both spoken and written contexts. Although software is available to teach figurative language to children and adolescents, it is our feeling that improvements are needed in the existing programs. Software should be reviewed carefully before it is used with students, just as standardized tests and other clinical and educational materials are routinely scrutinized before use. In this article, four microcomputer programs are described and evaluated. Suggestions are then offered for the development of new types of software to teach figurative language.

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